This is a finely written account, so far as it goes, of the British Secret Service (aka SIS, MI6) from 1909 to 1939. I would have given it 5 stars had it in fact been what it says on the cover, a "complete" "1909-1939" instead of being what it in fact is, a good but not complete account which more or less tails off to nothing after 1924.
I learned a lot in places, particularly about the assassination of Rasputin, that rather unpleasant but also misunderstood character. I knew a lady once who, as a young girl, had met several times Prince Yusupov, the main killer of Rasputin. I see from the account in this book that a person was involved of whose presence I had previously been unaware, namely Rayner, a British intelligence operative. It is claimed that Rasputin was not only beaten and killed but, in the interim time, tortured for information wanted by the British. The torture/beating was so severe that, it is said, Rasputin's testicles were "crushed flat". Not nice. The book also claims that the final fatal shot, after Rasputin's still living body was pushed almost under the ice of the winter Niva, was fired by Rayner, from his service revolver (a Webley, like the one shown on the cover of the book).
This story may be credible. Rasputin had opposed the pointless war with Germany (1914-1917) which, again as Rasputin predicted, would lead to the end of the Romanov dynasty and the country being taken over by devils until the "nobles" returned over two decades later (presumably he meant the officers of the Wehrmacht and SS). This last prediction is not in the book.
I should have liked to have given the book the full monty, but how can I, when the section 1924-1939 (1924 meaning the establishment of Soviet power on a state basis as the Soviet Union/USSR ---official foundation having been 1922--) is so slight?
Otherwise, a good read.